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Dyeing of cotton with madder using (bio)mordants: effects on fastness and UV protection properties
(Wydawnictwo Politechniki Łódzkiej, 2022) Alves, Cátia; Fernandes, Marta; Rodrigues, Rui; Zille, Andrea
This work aimed at studying the dyeing of cotton fabrics with madder extract using two biomordants, quebracho tree extract (Schinopsis spp.) and laccase. Pre-treatment with quebracho increased the colour strength, washing and UV light fastness, and UV protection, while laccase only shows an increase in the UV light fastness. The application of biomordants together with the metal ones (aluminium or iron salts) led to an improved UV light fastness compared to the samples mordanted only with metal salts. Meanwhile, although the colour strength was lower than in the metal-mordanted samples, greater UV protection factors were obtained in the samples pre-treated with quebracho or laccase and iron salt.
Sustainable and multifunctional natural fiber-based electric wire sheaths for smart textiles
(Wydawnictwo Politechniki Łódzkiej, 2022) Mehravani, Behnaz; Padrão, Jorge; Fernandes, Rui D.V.; Nicolau, Talita; Alves, Cátia; Ribeiro, Ana I.; Peixoto, Joaquim Jorge; Carvalho, Hélder; Zille, Andrea
Envisioning the development of sustainable products for improvement of daily life quality, a cable-like composite using natural fibers was developed to be potentially used in smart textiles. Natural fibers such as jute and hemp were used along with Bekinox®VN yarn. Bekinox®VN is a stainless steel conductive yarn often used in intelligent textiles within a wide range of applications such as antistatic, power and signal transfer, thermal conductivity or even as a heat resistant sewing yarn. Furthermore, applying a chitosan coating on the surface of the sheath will confer antibacterial properties, thus preventing the colonization and proliferation of bacteria, as well as natural fiber degradation. The chitosan coating was applied by a pad dry method. Tests were performed to evaluate the mechanical, electrical and antimicrobial properties. The results displayed that the best tensile strength was obtained for hemp fabric followed by cable composite. The antimicrobial properties were improved with the coating of chitosan and demonstrating excellent results against Gram-positive and Gram-negative bacteria. Although chitosan reduces the mechanical strength of the sheath, it confers antibacterial activity, which not only will preserve the fiber in the structure but will also protect human skin against possible crosscontaminations.